Re: [PATCH v3 17/25] dt-bindings: panel: Add Bananapi S070WV20-CT16 ICN6211 MIPI-DSI to RGB bridge

[Andrzej Hajda]

On 26.10.2018 16:43, Jagan Teki wrote:
> Bananapi S070WV20-CT16 ICN6211 is 800x480, 4-lane MIPI-DSI to RGB
> bridge panel, which is available on same PCB with 24-bit RGB interface.
>
> So, this patch adds DSI specific binding details on existing
> dt-bindings file.
>
> Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> ---
> Changes for v3:
> - Use existing binding doc and update dsi details
> Changes for v2:
> - none
>
>  .../display/panel/bananapi,s070wv20-ct16.txt  | 31 +++++++++++++++++--
>  1 file changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt b/Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt
> index 35bc0c839f49..b7855dc7c66f 100644
> --- a/Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt
> +++ b/Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt
> @@ -1,12 +1,39 @@
>  Banana Pi 7" (S070WV20-CT16) TFT LCD Panel
>  
> +S070WV20-CT16 is 7" 800x480 panel connected through a 24-bit RGB interface.
> +
> +Depending on the variant, the PCB attached to the panel module either
> +supports DSI, or DSI + 24-bit RGB. DSI is converted to 24-bit RGB via
> +an onboard ICN6211 MIPI DSI - RGB bridge chip, then fed to the panel
> +itself

As I understand this is display board, which contains 'pure' RGB panel
S070WV20-CT16 and optionally ICN6211 DSI->RGB bridge.
These are separate devices, just connected by vendor to simplify its
assembly. Why don't you create then bridge driver for ICN6211 and RGB
panel driver for S070WV20-CT16 - it looks more generic.
Then you can describe both in dts and voila.
Creating drivers for every combo of devices (panel + bridge), just
because some vendor sells them together seems incorrect - we have
devicetree for it.

Regards
Andrzej


> +
>  Required properties:
> -- compatible: should be "bananapi,s070wv20-ct16"
> +- compatible:
> +  for 24-bit RGB interface, use "bananapi,s070wv20-ct16"
> +  for ICN6211 MIPI-DSI to RGB bridge, use "bananapi,s070wv20-ct16-icn6211"
> +
> +Required properties for RGB:
>  - power-supply: see ./panel-common.txt
>  
> +Required properties for MIPI-DSI to RGB:
> +- reg: for DSI virtual channel used by that screen
> +- avdd-supply: analog regulator dc1 switch
> +- dvdd-supply: 3v3 digital regulator
> +- reset-gpios: a GPIO phandle for the reset pin
> +
>  Optional properties:
> -- enable-gpios: see ./simple-panel.txt
> +- enable-gpios: see ./simple-panel.txt(not available in MIPI-DSI to RGB bridge)
>  - backlight: see ./simple-panel.txt
>  
>  This binding is compatible with the simple-panel binding, which is specified
>  in ./simple-panel.txt.
> +
> +Example:
> +panel@0 {
> +	compatible = "bananapi,s070wv20-ct16-icn6211";
> +	reg = <0>;
> +	avdd-supply = <&reg_dc1sw>;
> +	dvdd-supply = <&reg_dldo1>;
> +	reset-gpios = <&pio 3 6 GPIO_ACTIVE_HIGH>; /* PD6 */
> +	backlight = <&backlight_dsi>;
> +};